Rick Santorum says nudity is the problem.

Rick Santorum doubled down Sunday on a campaign promise to crack down on the distribution of explicit pornography if elected president, saying exposure to the content "can be very damaging."

A position paper on Santorum's campaign website argues that current obscenity laws already prohibit the distribution of "hardcore (obscene) pornography," and that the Obama administration has failed to enforce these restrictions. As president, Santorum says he would instruct his attorney general to prosecute those who distribute content his administration deems "obscene."

"We would, of course, as president enforce those laws, because obviously Congress in its wisdom understood that hardcore pornography is very damaging, particularly to young people, and that exposure on the Internet can be very damaging," Santorum said during an interview on ABC's "This Week." "There are laws against purveying hard-core pornography. And that--we have attorney generals in the country, at least under the Bush administration, who did prosecute that. And this administration isn't. And I simply said I would follow the law, which I know in the case of Barack Obama can be somewhat of a hefty challenge for him, but we're going to do it as president."

Santorum, however, has yet to provide a specific definition of what kind of pornography his attorney general would prosecute. Under former President George W. Bush, the Justice Department focused primarily on small distributors that produced what it considered extreme content, but largely left the major production studios alone.

In interviews with Yahoo News last week, porn industry leaders--who produced their content throughout the Bush Administration--said they weren't worried about Santorum's threat to shut down their business.